FATP4 Switches Cellular Lipid Utilization via the PI3K-AKT Pathway in Goat Preadipocytes.

Area of Science:

• Molecular Biology
• Animal Science
• Lipid Metabolism

Background:

• Fatty acid transporter 4 (FATP4) is crucial for lipid metabolism, but its role in intramuscular fat (IMF) deposition in goats is unclear.
• Understanding FATP4's function is key to improving meat quality through IMF regulation.

Purpose of the Study:

• To investigate the role of FATP4 in goat intramuscular preadipocyte differentiation and lipid deposition.
• To elucidate the molecular mechanisms, particularly signaling pathways, involved in FATP4's function in goat adipocytes.

Main Methods:

• Cloning and sequence analysis of the goat FATP4 gene.
• In vitro studies using goat intramuscular preadipocytes with FATP4 knockdown (siRNA) and overexpression.
• RNA sequencing (RNA-seq) and KEGG pathway analysis to identify differentially expressed genes (DEGs).
• Validation of signaling pathway involvement using specific inhibitors (e.g., AKT inhibitor LY294002).

Main Results:

• FATP4 expression peaked during goat preadipocyte differentiation.
• FATP4 knockdown enhanced lipogenesis and lipid deposition but inhibited cell proliferation and decreased apoptosis.
• FATP4 overexpression promoted proliferation and suppressed apoptosis, with only minor effects on lipid deposition.
• RNA-seq identified 467 DEGs, enriched in Focal adhesion, HIF-1, and PI3K-Akt pathways.
• FATP4 knockdown increased PI3K expression; blocking the PI3K-Akt pathway rescued FATP4 knockdown phenotypes.

Conclusions:

• In goat intramuscular preadipocytes, FATP4 prioritizes fatty acid utilization for cell proliferation over lipid deposition via the PI3K-Akt signaling pathway.
• These findings provide mechanistic insights into IMF formation regulation at the cellular level.
• The study offers theoretical basis for enhancing meat quality by manipulating IMF deposition.